Mounting surfaces, such as the mounting surface of a rail or molded clip, are commonly used to mount devices. Typically, rails of a common type define a common arrangement for the mounting surface. One type of mounting rail is the xe2x80x9cDINxe2x80x9d type standard, also known as a xe2x80x9cDIN rail,xe2x80x9d as defined by the European Standards DIN EN 50022, xe2x80x9cSpecification for Low Voltage Switchgear and Control Gear for Industrial Use. Mounting Rails. Top Hat Rails 35 mm Wide for Snap-On Mounting Equipmentxe2x80x9d. Devices such as programmable logic controllers (xe2x80x9cPLC""sxe2x80x9d), Remote Terminal Units (xe2x80x9cRTU""sxe2x80x9d), protection relays, terminal blocks, fault recorders and meters are typically supplied with hardware, integrated or external, which allows the device to mount to DIN rails for installation and use.
Meters include watt-hour or revenue meters of the type used by energy suppliers to accurately measure electrical energy delivered to customers for the purposes of billing and/or collecting revenue, and power quality meters having power quality monitoring, detection and reporting capabilities. As mentioned above, these devices are often configured to mount or dismount to standard mounting devices, such as a DIN rail, by means of mounting hardware. This permits multiple devices to be conveniently located in a small area.
Known DIN rail hardware is either separately attached to the device or an integral part of the device. In either case, the hardware is typically complex and contains several pieces and moving parts and, as a result, the hardware is often costly to manufacture and, because of the multiple parts, more susceptible to breakage. Accordingly, there is a need for an improved, simplified mounting enclosure that allows the device to be mounted to a DIN rail or other suitable type of mounting surface without adding unnecessary complexity to the device design or manufacture.
Further, the tool used to injection mould plastic is typically split into two parts: the core and the cavity. The core and the cavity, when pressed together, have a space that reflects the shape of the part being injection molded. Molten plastic is injected into this space and, upon cooling, when the core and cavity separate the part is removed. It will be appreciated that a complex part having undercuts or blind cavities will require moving parts inside the core or cavity that must retract before the mold core and cavity can be separated. Further, because machine runtime is included in the manufacturing cost of the part, the step of opening and closing the mold can cause significant per-part cost increases if the mold is designed such that moving parts are required in the mold.
Molds that require moving parts are typically also more expensive to build and maintain and are further susceptible to breakage and reliability concerns. Other securing components utilized in the molding process known in the art include metallic securing parts incorporated into the mounting portion. These parts are added during the molding or assembly process, such as ultrasonically welding, heat staking or physically including them in the mold before plastic injection. This results in a number of operations that must be completed to produce a final mounting portion or device, thereby increasing the part cost.
Thus, there is a need for a reliable, simplified one part, low cost DIN rail mounting feature that can be integrated into a device. There is also a need for an integrated DIN rail mountable device manufactured with a process that contains no moving mold parts.
The preferred embodiments relate to an apparatus for mounting or dismounting a device on a mounting surface, for example, the mounting surface of a rail, a molded clip or the like. In a preferred embodiment the apparatus contains a retaining mechanism that mounts to standard sized surface such as a DIN rail or other mounting surface including the same dimensions of the DIN rail. However, other dimensions for the mounting surface could be used. The retaining mechanism is designed with a geometry such that the tool used to injection mold the plastic material has no moving parts. The acts involved in injection molding a part are as simply closing the mold, filling the mold, opening the mold and ejecting the part.
In particular, the retaining mechanism includes a body. At least a portion of the body is movably positioned adjacent to the mounting surface. The apparatus also includes a locating feature connected with the body. The locating feature includes a first position that maintains a position of the body during a manufacturing operation and a second position that allows the body to move, e.g., between an open position and a closed position after the manufacturing operation has been completed.